Specifications

UV22HR will be fitted to new AD-8000 units, and will be available as an upgrade to most AD-8000s. For
availability information, check our Web site at http://www.apogeedigital.com/
UV22 Process Caveats
UV22 Encoding is intended to be applied at the final step in the signal chain before the actual master-
ing device. For example, if you are mastering a conventional 16-bit CD, but you have the ability to
employ higher-resolution devices earlier in the chain, you should keep your signal at the highest reso-
lution possible until the creation of the final master tape, and at that point apply UV22 to reduce the word-
length from high-resolution to the final 16-bit for Compact Disc.
We recommend that no additional process of any kind be performed on the UV22-processed data, as there is
a risk that the benefits may be compromised. Application of UV22 at other points in the signal chain is possi-
ble, but some care must be taken when applying the process.
Because of the addition of the UV22 signal, we do not recommend that you use the “full-strength” UV22
process more than once or twice on a signal. Multiple passes through the UV22 process could degrade the noise
floor of the system at the upper frequencies.
Experimentation with the NORMAL and LOW settings (SW 5 DIP switch setting) is recommended if you
intend to carry out multiple passes through the UV22 process. In the NORMAL mode, UV22 has been optimized
to capture the greatest amount of detail from the high resolution digital input. The NORMAL mode has the
added benefit of smoothing out the non-linearity of almost any DAC. Even with 16-bit sources, the UV22
process gives notably better results on inexpensive DACs.
When using the LOW setting, less of the detail is captured. The LOW setting maintains respectable perfor-
mance with a reduction in the UV22 “energy concentration” of 6 dB. The reduction in energy could be desir-
able when multiple passes on a signal are performed.
Recordings to be used in a sample or sound effects disc can be UV22 encoded if pitch shifting is not likely
to be employed, or if
pitch shifting upward only is to be used. Pitch shifting downward on processed signals
risks making the UV22 energy concentration audible.
You
may experience problems with UV22 processing on signals that are destined for “lossy” compres-
sion systems, ie systems in which the compression system actually removes significant amounts of
information from the data stream in such a way that it can never be recovered, such as those tech-
niques used on the Internet. The UV22 process encodes so much detail that there is a small possibility that the
compression algorithms could cause audible artifacts on UV22 processed material. The same caveat may also
apply to other word-length reduction systems such as “noise-shaping”. The exact effects may vary according to
the program material and if possible you should test the material first.
UV22 is entirely unaffected by lossless compression schemes such as MLP (Meridian Lossless Packing), the
compression scheme used in DVD-Audio; and you should not notice any problems with common perceptual
coding schemes such as Dolby AC-3, MPEG-2 or DTS.
The AD-8000 features the capability to use UV22 to reduce the digital word length from the AD-8000’s stan-
dard 24 bits to either 16 or 20 bits. This is set by means of rear panel DIP switch SW2: the default (OFF) selects
16 bits and ON selects 20 bits. If you are using UV22 to adjust the word length of the output from your AD-
8000, be sure to set this switch to the resolution of your destination system.
Appendix III: Interfacing the AD-8000
with typical MDMs
The following pages include diagrams showing how to interface the AD-8000 with ADAT and DA-88
machines, including different synchronization requirements.
AD-8000 Operating Manual
Page 25